Jack



FIG. 1 is a front perspective view of the jack;

FIG. 2 is a right-side view of the jack:

FIG. 3 is a left-side view of the jack;

FIG. 4 is a rear view of the jack;

FIG. 5 is a front view of the jack;

FIG. 6 is a top view of the jack; and,

FIG. 7 is a bottom view of the jack. 

The ornamental design for a jack, as shown. 